


I Can See The Green Light (I Can See It In Your Eyes)

by agirlnamedtruth



Series: Sins [3]
Category: Merlin (TV)
Genre: Alternate Universe - Modern Setting, Alternate Universe - Summer Camp, Alternate Universe - Twins, Come Swallowing, Comeplay, Dirty Talk, Explicit Language, Explicit Sexual Content, Face-Fucking, Incest, Jealousy, M/M, Oral Sex, Orgasm Denial, Possessive Behavior, Rough Oral Sex, Sexual Fantasy, Sharing, Sibling Incest, Twincest
Language: English
Status: Completed
Published: 2013-10-15
Updated: 2013-10-15
Packaged: 2017-12-29 11:46:19
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,089
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1005050
Author URL: https://archiveofourown.org/users/agirlnamedtruth/pseuds/agirlnamedtruth
Summary: <blockquote class="userstuff">
              <p>Mordred is jealous of the new boy, Arthur. Merlin convinces him there could be some fun in sharing.</p>
            </blockquote>





	I Can See The Green Light (I Can See It In Your Eyes)

**Author's Note:**

  * For [sksdwrld](https://archiveofourown.org/users/sksdwrld/gifts).
  * Inspired by [He Ain't Kinky, He's My Brother](https://archiveofourown.org/works/1002862) by [sksdwrld](https://archiveofourown.org/users/sksdwrld/pseuds/sksdwrld). 



> Timestamp for the great [He Ain't Kinky, He's My Brother](http://archiveofourown.org/works/1002862) by [sksdwrld](http://archiveofourown.org/users/sksdwrld/pseuds/sksdwrld). You'll need to read that first for this to make sense.
> 
> Title taken from Florence and The Machine's [Over The Love](https://www.youtube.com/watch?v=ZX7aPZ35wxQ).

Merlin was waiting for him on one of the two beds they shared. When Merlin hadn’t been at lunch, Mordred had known he’d be here. He’d not clapped eyes on him since breakfast, it was almost like he _knew_ he’d done something wrong. It didn’t hurt that he had done something wrong, very wrong.

“Like the show, did you?” Merlin asked, raising an eyebrow and moving to get up. Mordred held up a hand to keep him where he was.

“You’re shameless, you know,” Mordred said, tone caught between disapproving and impressed. Merlin always had been a cockslut but usually he was satisfied with what Mordred offered him. But he also liked to tease, play off Mordred’s need to know that he owned him in every way he could. That they shared everything but only with each other.

“And you’re no fun.” Merlin pouted, his eyes moving over Mordred’s body as he approached the bed.

“Passing you around like you’re the dinner rations isn’t my idea of fun and you know that.” Mordred stared him down and Merlin rose up to the challenge, propping himself up on his elbows and angling his jaw so his neck was fully bared.

“Jealous?” he asked, barely above a whisper. He knew the answer and they both knew he’d get a lie.

Mordred leaned down, as if for a kiss. Merlin drew in a breath ready but Mordred stopped just short. “Not in the slightest. I mean, look at you...”

“Fucker,” Merlin swore, letting go of the breath he’d held and turning his head away defiantly. Mordred followed his lead and straightened up.

“You’re too easy, dear brother of mine,” Mordred sighed, almost sadly. “One of these days I’ll walk in on the wrong charade and the rumours will cease to be rumours.”

Mordred turned to leave, believing he'd made his point. There'd be another one that caught Merlin's eye and another after that; it was just the way his brother was made. Eager to share himself with the world, wanting to make everyone happy while Mordred didn't give a damn about the world, it could burn so long as Merlin alone was happy. 

He thought he had successfully put this particular crush of Merlin's to rest but Merlin cleared his throat, stopping Mordred before he got to the door.

"I want him, Mordred," Merlin said seriously.

Mordred was glad he had his back turned so that Merlin didn't see the dark look that flashed through his eyes, betraying him.

"You're mine," Mordred reminded him, glaring at the door frame. "I will not stand by and let you leave me for that... posh tart."

He heard Merlin stand and felt his hand on his shoulder, stroking, trying to calm him. Mordred wanted to jerk away from the touch but he couldn't, not ever. Merlin was more a part of him than his own flesh; he couldn't pull away without tearing himself in the process. He let Merlin press himself to his back and bring a hand up to curl in his hair. He let Merlin bring his lips close to his ear and whisper.

"I want him for both of us."

Mordred shivered. Merlin's hot breath on him and his words... Mordred couldn’t deny it was a pretty picture to imagine. Merlin gasping and moaning, impaled on another's cock for his viewing pleasure. Perhaps if he called the shots, if he told Merlin what to do, what he was allowed to do. Perhaps it could be something that wasn't entirely unendurable. Fuck, it could be hot in an ideal world - but this wasn't an ideal world. In an ideal world Merlin would be proud to be his lover, his love, as well as his twin. This wasn't an ideal world, not for them at least.

"He'd never agree to that," Mordred said finally and Merlin's arm came around his waist, squeezing because he hadn't said no outright. "The pretty boy will never let me join in. It's you he wants. He won't want me too."

Mordred tried not to let bitterness seep into his words. He was just stating facts. Even if the boy could accept what they were, what they did and what they were suggesting, he wouldn't want him. He only had eyes for Merlin, which Mordred couldn't blame him for. Everybody wanted Merlin, nobody ever wanted him. He was too dark, too creepy. He said the things most people would never think of saying. When he made a threat, it was _never_ empty. In all the rumours, it was always him corrupting Merlin. He’d do anything for Merlin. _Anything_. Mordred felt another twist of jealousy. If he was lucky, the best he could hope for was that the boy would let him watch without asking too many questions.

Mordred was dimly aware of Merlin's hands slipping down to his hips and he let Merlin turn him so they were facing. He knew, inevitably, he would give Merlin what he wanted. Merlin knew it too. The knowledge passed between them unspoken.

Merlin's eyes stared into his, reflecting the blue of his own. "Have you seen the way he looks at you? He might know I'm a safe bet but he thinks you're the dark horse."

Mordred let himself be drawn in, let Merlin tighten his hold.

"And when he sees us together, you know what he's thinking. He stares and he blushes and he wants to know. He wants us both, _together_. We could both have him, _together_. We could take him up to the island. You can ask him yourself; see if he comes on your invitation."

"And if he doesn't, if he only wants you?" Mordred asked, his own hands coming up to rest around Merlin's neck. He could feel Merlin's pulse racing under his fingers at the fact the idea was even being entertaining.

"Then nothing," Merlin answered, pressing his lips to Mordred's for the briefest moment before he finished his thought. "It's all or nothing." Merlin kissed him again, longer, harder. "Without you there is no me."

"You'll still be mine, I hope you know that."

Merlin nodded, his mouth crashing down on Mordred's again, teeth nipping at Mordred's lips until he opened up for him. His fingers tightened on Merlin's throat, a fiercely possessive hold that made Merlin moan into his mouth as he forced him backwards and down onto the bed.

"Prove it, show me how much you want it," Mordred offered. There was only one think that worried Merlin: the possibility of them being found out. It often played a serious part in their bargaining, a test to see how far Merlin would go to get his way. 

"It's broad daylight, you mental case," Merlin scolded him but there was an affectionate smile plastered across his face, a laugh not far from his lips. "What about our co-workers, fuck, what about the kids?"

"All scoffing down fish fingers and jelly pots. Come on Merlin, we'll have to tell Arthur the truth for this fantasy of yours to happen. He could tell anyone if he wanted too." Mordred caught Merlin's jaw in his fingers, kissing him until he relaxed, turning Merlin’s own tricks back on him.

"He won't tell, he'd have to admit the very idea makes him hot enough to come to us first," Merlin reasoned, reaching for Mordred's belt and positioning him just right. If he stood a certain way, with Merlin sitting on the bed, a casual glance through the window would only show Mordred's back.

More than a causal glance and they were fucked.

Mordred tried not to let that thought go straight his cock. It was already painfully pressed against the zip of his jeans, begging for Merlin to release it. It was all Mordred could do not to moan when his wish was granted and Merlin's long fingers curled around his length, pulling it free.

"Tell me what you want," Merlin asked, blue eyes staring up at him innocently even as his mouth hovered mere inches from the head of his cock.

"Suck it," Mordred said, raising his eyebrows. Merlin didn't usually need to be told. Rather, he had to be held off it more often than not.

"Obviously," Merlin muttered with a chuckle and then raised his voice again. "What do you want to happen with Arthur?"

As Merlin’s lips wrapped around his cock, Mordred found himself giving an honest answer. “I don’t know.”

Merlin looked up at him, raising an eyebrow as if to say _well, I have a fair few ideas if you want to trade places_.

Mordred glared down at him, clearly telling him _not a chance._

But he honestly didn’t know, not quite. Part of him wanted Arthur to tell them to get lost so that he could keep Merlin to himself. But if he agreed...

“If he agrees...” Mordred started and picked the first image that came into his head. “I want to watch him fuck you. I don’t care how but you’ll keep your eyes on me all the time, you’ll know I’m letting him fuck you, this pretty little posh tart of yours.”

Merlin moaned around his cock, reaching down to unzip his own jeans before Mordred noticed him. “Oh no you don’t, that’s not part of the deal.”

Merlin made an indignant noise and grazed his teeth along the side of Mordred’s dick, gentle enough to only prove his frustration and nothing more.

“Then if I let the pretty slut come in you – or on you – I’ll match him.” Mordred drew in a sharp breath and grabbed Merlin by the hair, slowing his furious movements and pulling him off his cock. “Calm down, love.”

“Make me,” Merlin dared, pressing a kiss to the skin his teeth had scraped over. “Love.”

Something curled in Mordred’s stomach, desire or possessiveness again, he was starting to lose track of which was which. But whatever it was made him tighten his grip on Merlin hair and drag him back to the head of his cock, pushing in until Merlin let out a small squeak that indicated he couldn’t take anymore. Mordred relented, pulling back slightly so he could push his hips forward again, this time knowing where the line was and pushing Merlin to the limit with every snap of his hips. Merlin, to his credit, took it without complaint, his hands coming up to cup Mordred’s arse, kneading it in time with Mordred’s thrusts.

“I’ll match him,” Mordred said to himself. “I’ll best him.”

Merlin made a muffled sound but Mordred knew what he’d say anyway so he didn’t stop.

“Don’t worry; I’ll get you back here first. We wouldn’t want to scare the poor lamb.” Mordred paused, releasing Merlin’s hair and letting him have free rein again. Merlin rewarded him by grabbing the base of his cock with one of his hands and steadying himself against Mordred’s thigh with the other, his mouth sliding up and down like he was trying to break the record for how fast he could suck a ice lolly.

Merlin looked up at him, knowing by some magic, like he always did, that he was close and all he needed was those blue eyes, begging him wordlessly to come. Mordred’s hands tightened into fists and he tried to keep his legs locked, determined they wouldn’t give out on him as he came, Merlin swallowing every drop and trying to milk him for more.

Mordred smiled, seeing Merlin through a haze. The pretty posh tart would be lucky to have him.

“I bet we could show him a thing or two though,” Merlin said, echoing Mordred’s thought before he dragged the back of his hand over his mouth like the perfect little whore he was. Mordred looked at him for a moment in wonder and then remembered the last comment he’d made aloud – about scaring the boy.

“We’ll see.” Mordred promised and leaned down, kissing Merlin, his mouth still wet with spit and come. He could taste himself on Merlin’s tongue and it was almost like tasting Merlin himself.

When Merlin arched up into the kiss and tried to direct Mordred’s hands to his jeans, Mordred pulled away with a little laugh. Merlin couldn’t get everything he wanted or it would go to his head, a dangerous notion.

“Oh no, love, that’s for the Pendragon boy to deal with,” Mordred smiled before turning and walking to the door. He paused just in time to see Merlin pretend he wasn’t beaming. “Better hope he accepts my invitation, hadn’t you?”

**Author's Note:**

> The biggest thank you in the world to M (sksdwrld) for letting me play in this 'verse with her <3
> 
> As of 01/01/18, I'm opting to disable comments. [More information here](http://archiveofourown.org/works/13077201).


End file.
